Default Functions

On the client side

vcl_recv

This function is called when a new request enters. From this function, you can modify the behavior or content of the request and decide how to process it.

In this function, you should configure a backend to which the request should be sent.

vcl_(recv|miss|backend_fetch|backend_response|hash|deliver)

vlc_hash

Called after vcl_recv. In this function, the caching behavior is modified when storing the object in the cache.

vcl_miss

It is called immediately after looking up the object in the cache and only if it has not been found.

vlc_deliver

This function is called before sending the object to the client.

On the origin side

vcl_backend_fetch

This function is called before sending the request to the backend to retrieve the object.

vcl_backend_response

This function is called when the backend response arrives successfully.

The rest of the predefined functions in Varnish Enterprise Plus are not allowed to be modified by the user in Transparent CDN, to ensure the security and stability of our clients' sites at all times. However, you can check them out here.